There are some certain people that are hard to be around.  I once heard a christian speaker say that these types are called suckers.  The more you try to help them, to be there for them...."they suck the life out of you."  I remember the speaker saying there is a certain point where you have to cut the strings and realize that there is nothing more we can do and move on and live according to God's calling.  The speaker wasn't saying for us to be mean, rude, or anything terrible of the sort, but to just let go and move on.  It is hard to do this especially when the person or persons are those we dearly love.  I love these people, but when I allow them access to my daily life, I feel drained, despondent, worthless.  Everything our family stands for is confusing to them and weird....they make sure we know this, then they take it upon themselves to try to show us the true way.  Who is leading who at this point?  Am I leading them to Christ?  No, instead I am frustrated and weary.  Not a good place to be when the bible clearly lays out my role as wife and mother.  Wife and mother first...an encourager, a guide for my children, a helper for my husband, showing love, patience, kindness.  To be a testimony of faith.  Is it even possible when we allow these types access into the innermost part of our lives, sucking the life out of us?  You know I believe it is good to take a step back from these type of people, still love them, still pray diligently for them, just stop allowing them to drag us around and down and where ever they feel that day. 
Hmm, easier said then done, but with grace and mercy accomplishable.